{
  "family": "redosdru",
  "sample_count": 12,
  "category": "ransomware",
  "description": "Trojan:Win32/Redosdru is a persistent, stealthy trojan and backdoor designed to breach endpoint defenses, establish a long-term foothold, and securely deliver secondary, high-severity payloads like ransomware, banking trojans, and botnet agents.<br><br><b>Understanding Redosdru</b><br>To an end-user, a Redosdru infection is typically invisible until a devastating secondary payload executes or data is exfiltrated. For threat intelligence analysts, Redosdru is a critical staging mechanism. It functions as an 'Initial Access Broker' tool. Its primary objective is to securely bypass endpoint defenses, profile the infected machine to ensure it is not a sandbox, establish a persistent backdoor, and reach out to a Command-and-Control (C2) server to pull down the final, destructive payload.<br><br><b>Execution and Evasion Strategies</b><br>Redosdru is commonly distributed via massive malspam campaigns containing weaponized attachments (like ZIP files or Office macros) or through exploit kits. Upon execution, it utilizes heavy packing and dynamic API resolution to evade static antivirus signatures. It drops a randomized executable into the `%Temp%` or `%AppData%` directory. It establishes persistence by creating a hidden scheduled task or modifying the Registry Run keys. Redosdru frequently injects its downloading routine into legitimate system processes (like `explorer.exe` or `svchost.exe`) to mask its outbound network traffic.<br><br><b>Indicators of Compromise (IoCs)</b><br>Threat hunters should investigate EDR alerts related to 'Suspicious Process Injection' or 'Anomalous Child Process Spawning'. Network logs will often reveal Redosdru reaching out to compromised domains using encrypted HTTPS traffic. The presence of unexpected, hidden scheduled tasks designed to execute randomly named binaries in the user's profile is a strong IoC. Memory analysis is necessary to extract the injected downloader modules and determine what payloads were requested.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1027",
    "T1547.001",
    "T1105",
    "T1055",
    "T1566.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1105",
      "name": "Ingress Tool Transfer",
      "tactic": "Command and Control"
    },
    {
      "id": "T1055",
      "name": "Process Injection",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder",
      "tactic": "Persistence"
    },
    {
      "id": "T1566.001",
      "name": "Phishing: Spearphishing Attachment",
      "tactic": "Initial Access"
    },
    {
      "id": "T1027",
      "name": "Obfuscated Files or Information",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Isolate the endpoint immediately to prevent Redosdru from downloading and executing its secondary payloads (e.g., ransomware).",
    "Audit the Windows Task Scheduler and Registry Run keys to identify and remove the Redosdru persistence mechanisms.",
    "Review firewall and proxy logs to identify the C2 domains Redosdru attempted to contact, and block them enterprise-wide.",
    "Capture a live memory image (RAM dump) to extract the injected Redosdru modules and identify the secondary payloads."
  ],
  "what_to_avoid": [
    "Do not close an incident simply because the initial Redosdru dropper was quarantined; always verify if secondary payloads were downloaded.",
    "Avoid relying solely on manual file deletion, as the injected processes will likely just recreate the dropped binaries."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}